1. Field of Invention
The invention relates to an electronic device having a detachable controller that controls a controlled part provided in a frame of the electronic device.
2. Description of Related Art
Conventionally, information machines provided with printing devices, such as serial printers, include a motor, a guide shaft, a carriage that is movable along the guide shaft, a recording head mounted on the carriage, and some mechanical driving mechanisms, such as a paper supply mechanism and a paper ejection mechanism. Such information machines include a control circuit board, which functions as a controller, to control the mechanical mechanisms, and this control is performed by applying a driving force given by a drive source, such as the motor to the mechanical driving mechanisms optimally.
However, upon control of the information machines, each element of a mechanical driving mechanism may have uncertain factors, such as size and shape errors, attaching position errors, and individual differences in motor skills. Accurate control cannot be performed unless these uncertain factors are considered.
For example, in a printer disclosed in Japanese Laid-Open Patent Publication No. 2001-347706, control information for correcting each uncertain factor of the printer is added to a standard program (firmware) and installed in a non-volatile memory (i.e., EEPROM) on a control circuit board to control mechanical driving mechanisms by the program modified based on the control information.
There are various kinds of control circuit boards for use in information machines according to various specifications and destinations. Such control circuit boards are manufactured on production lines in accordance with, for example, a cold district, a temperature region, and each country.
On product lines of the information apparatus, at an upstream side, control information common to each driving mechanism is obtained, a control circuit board is installed in an information apparatus, and the control information is installed in a nonvolatile memory (such as an EEPROM) on the control circuit board.
However, a unit test for obtaining the control information on each driving mechanism is a comparatively time consuming operation requiring the use of special jigs. For example, assuming that the unit test takes 10 minutes per information apparatus, it would be extremely inefficient as a product line process. Therefore, as shown in FIG. 10, a conventional production site is designed so that ten product lines 100, for example, are prepared with the corresponding inspection stations 110 each where unit testing is performed. Personal computers 110a and 120a are located and connected in communication with each other between the inspection stations 110 and an assembly station 120 where control circuit boards are installed. At the assembly station 120, the control information sent from each of the inspection stations 110 is installed in control circuit boards.
The operating efficiency is increased by performing the unit test at each of the inspection stations 110 and sending drive mechanisms from each inspection station 110 where unit testing is performed, for example, in increments of one minute, to the assembly station 120.
However, in this layout, the inspection stations 110 should be provided with the corresponding number of personal computers 110a, further communication equipment 130 should be required for connecting the personal computers 110a and the personal computers placed at the assembly stations 120. As a result, costs on facility investment are entailed.
In addition, elements (components) of a mechanical drive mechanism at shipment may be replaced due to consumption or malfunction. When an element of a mechanical drive mechanism is replaced with a new one, control information stored in a non-volatile memory on the control circuit board at shipment cannot be applied to a replaced element. The mechanical drive mechanism whose element has been replaced cannot be driven smoothly based on the control information at shipment.